Synchronizing clutch



Oct. 10, 1939. c PETERSON 2,175,911

SYNCHRONIZING CLUTCH 9 l 7' m e D d e 1 1 F Patented oot. 10, 1939 UNITED STATES PATENT OFFICE 2,175,911 SYNCHRONIZING cw'ron Carl D. Peterson, Toledo, Ohio Application December 7, 1938, Serial No. 244,445

3 Claims.

This invention relates to synchronizing clutches for change-speed transmission gearings, such as are used in motor vehicles, and has for its object a synchronizing mechanism by which a greater pressure can be applied to the friction section of the clutch preliminarily to the clutch engagement of the toothed section, when the clutch is being shifted to establish a drive through one gear ratio than when the clutch is being shifted to establish a drive through another gear ratio. For instance, greater pressure originating in the shifting lever is applied to the friction section of the clutch preliminarily to the clutching of one of. the toothed faces of the clutch when a shift is being made to establish a drivethrougha reduction gearing,.as second speed forward, than when the shift is being made to establish direct drive, or first speed forward, the

additional pressure effecting complete synchro- 30 nization as quickly through the reduction gearing as through the higher ratio or direct drive.

The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed.

5 In describing this invention, reference is had to the accompanying drawing-in which like characters designate corresponding parts in all the views.

Figure 1 is a fragmentary sectional detail view 30 of a transmission gearing embodying this synchronizing clutch.

Figure 2 is a fragmentary sectional view on the plane of line 2--2, Figure 1. I

Figure 3 is a fragmentary view of the sleeve or friction section showing-the construction of. the synchronizing 'slot.

In the drawing, I designates the drive shaft; 2 the transmission shaft, and 3 the counter shaft of a change-speed transmission gearing, the' 0 shafts I, 2 being mounted in axial alinement .and

the shaft 2 having a pilot bearing at 4 in the shaft I or in the gear 5 on said shaft. The shaft I and gear 5 are usually a unitary structure or a stem gear. These shafts are journalledin suit- .15 able hearings in the end walls of the gear box 6.

. I is a gear mounted on and normally rotatable.

about the transmission, shaft 2 and forming part of a train of gears constituting an indirect drive 1 between the shaft I and the shaft 2. This train 50 of gears, in addition to the gears 5 and Lincludes gears 8 and 9 mounted on and rotatable withthe counter shaft and meshing respectively with the gears 5 and I.

III designates generally the synchronizing 55 clutch. This includes an inner section II mountratios, it being shiftable to the left (Figure 2) to establish direct .drive relation between shafts I, 2

and to the right -to establish an indirect drive 10 through reduction gearing 5, 8, 9 and I. The inner section II is formed with toothed clutch faces I4 and I5 on opposite sides thereof for coasting withclutch faces I6 and IT on the gear 5 and the gear I respectively. The friction sec- 16 tion I2 is in the form of a sleeve having truncated conical friction faces I8 and I9 at its opposite ends for coacting with complemental friction faces on the gears 5 and 1. As is well understood, the friction section coacts with the friction faces 20 of the gears 5 and I in advance of the engagement of the toothed faces I l and I5 or the toothed faces I6 and I1.

The inner section is shown as formed with radially extending posts 20 having pins 2 I- seated therein which extend through slots 22 in the sleeve I2 and into the collar I3 and establish a connection between the collar I3 and the toothed section II. The inner section II is also formed with posts 23 alternating with the posts 20 and carrying spring-pressed poppets 24 which coact with cam-shaped notches 25 in the sleeve I2 and serve to yieldingly transmit axial shifting movement of the inner section II to the friction section I2 to engage the friction faces in advance of the toothed faces.

The construction of the synchronizing clutch per se thus far described forms the subject matter of my pending application, Serial No. 219,421,

filed July 15, 1938. This invention relates to means by which greater pressure may be applied to the sleeve I2 through the collar I3 to apply a greater force-to the friction section when the shift is being made, as to the right (Figure 1) to, establish indirect drive, than when the shift is being made to the left to establish direct drive. This means comprises the slot 22 which extends lengthwise ofthe sleeve and has a wider intermediate portion 21, the walls of which are of such form as to ofier greater obstruction to the pin or pins 2I when the shift is being made in one direction than in the other, and hence to press one friction face harder than the otherfriction face, to prevent clashing of the toothed faces that would otherwise occur due to premature engagement of the toothed or jaw faces before synchronization is completed. The pin 2|, which is normally arranged in the wider portion 21, is of less width than the wider portion and is movable into the narrower end portions 28 of the slot, when a shift is made in one direction or the other from neutral and slidably fits the narrower end portion. when the clutch I. is shifted in one direction or the other to bring the friction face I. or I! into clutching engagement with the complements] friction face of the gear 5 or gear I, further shifting is blocked by the portions of the walls of the wider portion 21 where they approach the narrower portions ll until the speeds are. synchronized.

When the shift is being made to establish the high gear or direct drive ratio, the synchronizingis effected quicker and with less pressure on the fric- -tion section I! than when the shiftismadetoestablish the indirect drive through the train of gears. This is due to the greater centrifugal effect of the rotating parts on the gear 1 than on the gear 5 or shaft l. Hence, the walls 29 of the wider portion where they approach the left hand narrow portion 28 of the slot 22 is at a small incline compared with that of the portion 30, where it approaches the other end portion 28 of the slot 22 into which the pin 2! passes when clutchin the gear I to the shaft 2, or, in other words, the portion offers agreater obstruction to shifting than the portion 29, so ,that the operator applies more pressure to the shifting lever, and hence to the collar ll, toothed section II and through the pin 2| to the sleeve [2, causing increased friction to effect the synchronizing between the sleeve l2 and the gear 1. This greater pressure reguired brings about a quick synchronization through the friction face 19.

In operation, during shifting of the clutch Ill to the left, the pin is blocked by the small incline 28 until synchronization occurs, and the shift completed without applying heavy pressure to the sleeve i2. When the shift is made to the right, the pin is blocked by the more abrupt inclines III and the greater pressure thereagainst,

opposite directions from neutral to establish drives through different gear ratios in a changespeed transmission gearing, said clutch compris-, ing a toothed clutch section rotatable with a shaft of the gearing and shiftable axially thereof in opposite directions from neutral and having toothed faces on opposite sides thereof for coacting with toothed faces of gears to be alternate 1y clutched to the shaft, and a friction section having friction faces on opposite sides thereof for alternately coacting with friction faces on the gears to be alternately clutched to the shaft in advance of the clutching engagement of the toothed section, a shifting collar encircling the friction section and slidable axially thereon, and

connected to the inner section to shift the same, means for yieldingly transmitting the motion of the toothed section to the friction section, and a synchronizing connection between the friction section and the toothed section comprising means for positively applying shifting pressure from the toothed to the friction sections preliminarily to the clutching engagement of the toothed section, said connection embodying means for applying greater shifting pressure to the friction section from the toothed section preliminarily to clutching engagement of the toothed section, when the toothed section is shifted in one direction than when the clutch section is shifted into the other direction from neutral.

2.- In a double synchronizing clutch operable in opposite directions from neutral to. establish drivesthrough diflerent gear ratios in a changespeed transmission gearing, said clutch comprising an inner \toothed section rotatable with a shaft of the gearing and shiftable axially thereof in opposite directions from neutral and having toothed faces on opposite sides thereof for coacting with toothed faces oflelements to be clutched alternately to the shaft and a friction section including a sleeve encircling the toothed section and having friction faces at itsjopposite ends for alternately coacting with friction; faces on the elements to be alternately clutched to the shaft in advance of the clutching engagement of the toothed section; a shifting collar encircling the sleeve and slidable axially thereon and connected to the inner section to shift the same, and means for initially 'yieldingly transmitting the motion of the toothed section to the friction section to engage one or the other of the friction faces preliminary to the clutching engagement of the toothed section, the sleeve being formed with a lengthwise slot having a wider intermediate portion, and a collar being connected to the toothed section by posts extending through the slot of less width than the intermediate wider portion of the slot and normally arranged therein, and slidably fitting the end portions of the slot, the posts coacting with the walls of the wider portion of the slot where they approach the narrower portion to block-shifting of the toothed section until the speeds are synchronized through the friction section, the walls on one side of the wider portion where they approach one end portion of the slot being of a greater incline than the corresponding walls at the other side of the wider portion.

a. In a double synchronizing clutch including an inner toothed section having clutch teeth on opposite sides thereof, an outer friction synchronizing sectionhavingfriction clutch faces on opposite sides thereof, shifting means connected to the inner section, and yielding means between the sections for initially transmitting the shifting movement of the inner section to the outer section, the inner section having a radial projection, and the friction section having a slot through which theprojection extends, the slot including end portions, and an intermediate portion of greater width than the end portions, the projection slidably fitting the end portions and being of less width than the intermediate portion, the walls of said intermediate portion where they approach the end portions being of different inclinations out of planes at a right angle to the direction of movement of the projection into the slot 

